Let’s go back to basics for a minute. How do you make your monsters? I remember in 3.5e there were deep and detailer rules, almost impossible to understand and follow, to make new monsters, a procedure that would take hours.
I hate that crap!
But OSR is different, here you can make a monster in under a minute, or five minutes if you really think about it. This is what I do.
https://magickuser.wordpress.com/2021/02/16/making-monsters-for-osr-games/